Chapter 42 - Animal Reproduction - 42.2 - Sexual Reproduction Involves the Union of Haploid Egg and Sperm - 42.2 Recap - Learning Outcomes - Page 901: 2

The egg’s cortical granules releases enzymes that stimulate the slow block to polyspermy. This is achieved by a flood of sodium ions that creates a charge across the plasma membrane and prevents further fusion of the games. By inhibiting polyspermy, only one sperm cell is permitted to fertilize with the egg and the embryo is given a chance to survive.

The egg’s cortical granules releases enzymes that stimulate the slow block to polyspermy. This is achieved by a flood of sodium ions that creates a charge across the plasma membrane and prevents further fusion of the games. By inhibiting polyspermy, only one sperm cell is permitted to fertilize with the egg and the embryo is given a chance to survive.